Detailed lightning risk assessment based on NFPA 780 using Sparkta Software.

1. Designing Lightning Protection Systems
using Sparkta
NFPA 780 Detailed Risk Assessment
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2. Lightning Protection Systems Optimal Design (Add… and Evaluate…)
 Optimal design is an iterative process which consist of adding one or few air terminals and evaluates the risk components each
time.
 The air terminals are added in most likely lightning strike points.
 The process stops when the Risk Components are less than the tolerable limits.
Four Steps
 Step 1: Physical modeling
 Step 2: Initial Risk Assessment. Identify the most critical risk components.
 Step 3: Choose the protection measures needed to reduce the most critical risk components. If a Lightning Protection System is
needed, identify the most likely lightning strike points and add air terminals at these points.
 Step 4: Calculate the risk components. If one or more of the risk components are greater than its tolerable limit, than repeat
steps 3 and 4.

3. Example
 Industrial facility with multiple buildings
 Isolated structure
 Service: aerial, 200 m, with transformer
 Internal wiring: Unshielded
 Uw: 4 kV
 Type of structure: Industrial
 Type of surface: concrete
 10 flashes/km2/year

4. Physical data
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Roofs are modeled as quadrilaterals
Other shapes consist of two or more quadrilateral
Hexagon: 2 quadrilaterals
Octagon: 3 quadrilaterals
Settings for the simulation

5. Plan view

6. 3D view

7. Graphic Results

8. Results
 Strikes per year for each range of current
 Strikes per year for each roof

9. NFPA 780 Detailed Risk Assessment Using Collection Area Formulas

10. NFPA 780 Simplified Risk Assessment Using flashes per year from simulation

11. Risk components analysis
 R1, R2, R3 and R4 are higher than the tolerable values, lightning protection is required.
 The most representative risk components are:
 RB: Risk of Physical Damage Due to a Direct Strike to Structure
 RV: Risk of Physical Damage Due to a Direct Strike to Incoming Service
 To reduce RB an External Lightning Protection System is needed (air terminals and its down conductors and earth system)
 To reduce RV it is needed to install a Surge Protection System (SPDs) to protect the line.

12. Identify the most likely lightning strike roofs
 Add 4 air terminals and simulate

13. Graphic Results

14. NFPA 780 Detailed Risk Assessment Using flashes per year from simulation

15. Identify the most likely lightning strike roofs
 Add 23 air terminals and simulate

16. Graphic Results

17. NFPA 780 Detailed Risk Assessment Using flashes per year from simulation

18. Identify the most likely lightning strike roofs
 Add 13 air terminals and simulate

19. Graphic Results

20. NFPA 780 Detailed Risk Assessment Using flashes per year from simulation

21. NFPA 780 Detailed Risk Assessment Using flashes per year from simulation

22. Final Design

23. http://www.spartalightning.com/
sales@spartalightning.com